DE2337034A1 - HEAT-RESISTANT COMB-SHAPED STRUCTURE AND METHOD FOR MANUFACTURING IT - Google Patents

Description

Patent attorney

Dipl.-ing. A. Orüneckef

Dr.-Ing. H. Kinkelttey

Dr.-Ing. W. Stockmcir

8 Munich 22, Maximilianstr. 43

PH 6809

20th juV \ 1573

NISSAN MOTOR COMPANY, LIMTED 2337034

No. 2, Takara-raaclii, Kanagawa-ku Yokohama City, Japan

Heat-resistant honeycomb structure and process for its manufacture

The present invention relates to a heat-resistant honeycomb structure and a method for its production. This one proposed honeycomb structure is particularly useful in a heat accumulator of a heat exchanger of a gas turbine, as a flow rectification unit of a hot gas pipeline system or suitable as a catalyst carrier of a catalytic converter that is inserted into an exhaust system of an internal combustion engine is mounted to purify the exhaust gases passed through it. The present invention relates accordingly Another device for the passage of hot gases, in which the heat-resistant v / aben-shaped structure is built.

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The heat-resistant honeycomb structures currently used in Hot gas flow devices, such as heat accumulators, flow rectification units and catalytic converters are used, usually have a very low breaking strength, which is due to the brittleness of the honeycomb structure is due. Such honeycomb structures break easily without anything worth mentioning Deformation when subjected to relatively low loads or as a result of mechanical vibrations. There is also a risk breaking or cracking if the structures show an irregular heat distribution or thermal stresses, In particular, tensile stresses are exposed, which are the result of thermal shocks when the honeycomb-shaped structure is rapidly heated or cooled Formations with large temperature differences are.

A honeycomb structure generally consists of a number of corrugated layers which are separated from one another by intermediate layers to which the corrugated layers are attached along their backs. The intermediate layers are so thin that the honeycomb-shaped Structure is extremely fragile, especially at its edges. To keep the honeycomb structure in working position, usually serve attacks on the. Edges of the honeycomb Rest of the structure so that the honeycomb structure does not move in the longitudinal direction out of the prescribed working position can remove. Palis for some reason it happens that the honeycomb structure is in hard contact with the stops during installation comes, the honeycomb structure can easily break at its edges or in their vicinity. Can the honeycomb structure slide in the working position along the stops, this has a strong abrasion of the edges of the honeycomb structure result. So far it has proven difficult to get the honeycomb structure in the prescribed working position safe to support and hold. The present invention is intended to eliminate this disadvantage, that is to say a honeycomb structure created v / earth, which on the one hand is break-proof and on the other hand

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can be held securely and firmly in the prescribed working position without the gas circulation being impaired during operation is affected.

A heat-resistant honeycomb structure is according to the invention: characterized by several corrugated layers and intermediate layers of porous Keraraikramaterial, which are arranged in alternating order on top of each other, the corrugated layers have parallel backs, which at their upper and lower Ab-Echnitteu on the surfaces of adjacent Zv .Dschenlagen fixed rind, WOdUi ¹ Cb a number of through-channels are formed, which extend rieh, parallel to the bridges of the corrugated layers and are delimited by the back and the surfaces of the adjacent intermediate layers, and by at least one porous cde3? non-porous outer layer made of Kerainikiümaterial, v; which surrounds the structure of the gowe]] th layers and intermediate layers ira essentially transversely to the back of the corrugated layers, so that? at least a large part (majority) of the passage channels is kept open at their rain-overlapping ends.

The above-mentioned poror.c Keraraikrnateriol building up the corrugated layers and intermediate layers is preferably an Alumiriumco-Iycl such as dichroic, (Fg, Fe) ₂ Al ₅ . (Si ₇₄ Al ₂ ) 0 ^ ₈ v. While the ceramic material making up the outer layer is "partially" the same or similar to the material used for the corrugated layers and intermediate layers. This Keramikniaterial used for the outer layer may, for example, β-spodumene, beta -LiAl (SiO. ₇₎ to be p, which forms a glassy layer after melting.

The honeycomb structure of the structure described above can produced by a method according to the present invention is preferably characterized by the following process steps:

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Creation of a structure of corrugated layers and intermediate layers in alternating sequence from a cardboard cover from a pulp with ceramic material distributed in it, with each corrugated layer lying between two intermediate bearings and the corrugated Layers have parallel ridges, which at their upper and lower portions to the formation of passageways to the Surfaces of adjacent interlayers are attached, firing the created structure at a temperature lower than the melting temperature of the ceramic material contained in the cardboard lid is to burn the cellulosic facers in the dispersion, to obtain a porous ceramic structure or "pastry" and wrapping the pastry substantially across the back of the corrugated layers in at least one layer of the Cardboard lid made of paper pulp containing your podumco parts is formed, and Bronnen the structure obtained a temperature close to the sintering temperature of the core Kxkwaterialr., that in which the corrugated layers and intermediate layers are raised Cardboard lid is included.

Another preferred method for making the one proposed here The honeycomb structure is characterized by the following procedural steps:

Creation of a structure from corrugated layers and intermediate layers in alternating sequence from a cardboard lid made of a pulp with ceramic material distributed therein, with each corrugated layer in between two liners come to lie and the corrugated layers have parallel ridges on their upper and lower portions to form through channels to the surfaces Adjacent intermediate layers are attached, wrapping of the sliding structure of corrugated layers and intermediate layers in alternating Follow essentially across the back of the corrugated Layers with at least one outer layer of cardboard cover made of the pulp with the ceramic material distributed in it

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is, wherein the ceramic material in the outer layer is a lower one As the ceramic material contained in the corrugated layers and spacers, has melting temperature, and Firing of the structure at a temperature in the range between the Schraelztemperaturen of the Kerainikmaterials in the corrugated Layers and interlayers and the ceramic immaterial in the Outer layer.

Another process for the production of the heat-resistant honeycomb-shaped structure is marked by the process steps:

Creation of a structure from several corrugated layers and intermediate layers in alternating succession made of a cardboard lid made of a paste with ceramic material distributed in it, v / obei. each one Layer comes to lie between two liners and the Corrugated layers have parallel ridges, which at their upper and lower portions adjoin the surfaces of adjacent ones Spacers are attached to a number of through channels to create that is parallel to the back of the · corrugated Layers extend and are bounded by the backs of the corrugated layers and the surfaces of the spacers, firing of the structure at a temperature below the melting temperature the ceramic material contained in the cardboard lid, spraying on of- particles of a ceramic material which becomes vitreous when melted onto the outer surfaces of the fired structure which are parallel to the backs of the corrugated layers so that at least a majority (majority) of the through channels in the The structure remains open at its opposite ends, and the already fired structure is burned together with the sprayed ones Particles at a temperature close to the sintering temperature of the Ceramic material building up the already fired structure.

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Experiments carried out with honeycomb structures, which after a by the methods described above showed that the slurry with ceramic material dispersed therein advantageously 7 to 15, preferably about 10 parts by weight of ceramic material, like mchroit, contains porridge to 1 part by weight.

The heat-resistant honeycomb structure according to the above "description constructed and manufactured, has an outer glass-like cover layer, e.g. made of ß-ßpodumene, or a porous one or non-porous cover layer made of a ceramic material, then "particle wise" is the same or similar to the ceramic material, E.g. dichroic, for the construction of the corrugated layers and intermediate layers, but greater mechanical robustness having. The outer top layer thus increases the mechanical ! Strength of the overall construction, especially the breaking strength of the edges of the honeycomb structure. This one The honeycomb structure disclosed not only has excellent heat resistance and sufficient current distribution capacity, rather, it can also be held and supported safely and securely in the working position. Its breaking or a premature one Abrasion is avoided even if there is an irregular heat distribution or thermal or mechanical shocks v / is suspended during operation.

Is the honeycomb structure according to the invention in a plant built in through which hot gases are passed, such as in a catalytic converter for use in the exhaust system an internal combustion engine, then the honeycomb structure described is a housing with .ein inlet and one Outlet assigned in such a way that the through channels in the structure at their opposite ends to the inlet and Open the outlet of the housing. A pair of stops are supported against the edges of the outer cover layer of the honeycomb structure at.

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Further features, details and advantages of the invention result can be seen from the following description of exemplary embodiments with reference to the drawing therein

Fig. 1 is a longitudinal section of a preferred embodiment a device according to the invention sum passing hot Gases;

FIG. 2 is a partially cut-away perspective view of a preferred embodiment of the invention; FIG. overheated ^? annular cylindrical structure which is part of the device of Fig. 1;

Fig. J) a perspective Tcxlansicht vdres Zv / ischeriaaufbaus ζην formation of the v / abenförrcigen structure,? From Fig. 2, v / whether the interjection structure can be produced according to the previously described first or second preferred embodiment of the inventive pen method;

K shows a perspective view of a hit-resistant v / abenförmii-yen structure which is produced according to the third preferred embodiment of the method according to the invention described above; and

5 shows a graphic representation of the temperature distribution over the cross-sectional area oiries according to the invention honeycomb structure.

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BATH ORIGINAL

It is assumed that the device shown in FIG Catalytic converter for arrangement in an exhaust system (not shown) of an internal combustion engine, with the help of this the exhaust gases are cleaned before they escape into the ambient air should be. However, this use is only to be understood as an example and the device is shown in FIG The structure could also be used as a current rectifying unit in a pipeline system of a hot gas system or as a heat storage unit a heat exchanger of a turbine can be used.

-The one in the exhaust system of the internal combustion engine is usually one The catalytic converter installed in the motor vehicle is intended to flammable residues in the exhaust gases, which "Oieisweise Burned hydrocarbons and carbon monoxide are completely oxidize or "burn off" or it should be in the Nitrogen oxides contained in exhaust gases are reduced. The unburned hydrocarbons passed through the catalytic converter, Carbon monoxide or nitrogen oxides can be found in the exhaust gases in reactions that are supported by a catalyst housed in the converter, v / ground, oxidize, reduce or replace κ and converted into harmless component! .ο before the The exhaust gases from the Auepuffanlage finally escape. One Apparatus of this type and suitable catalysts for this purpose are well known, so that a further description can be omitted.

The catalytic converter shown in FIG. 1 has an essentially cylindrical housing 10 which, in the present case, forms part of an exhaust system of an internal combustion engine. The cylindrical housing 10 is closed in the longitudinal direction before — young end end sections with an inlet 1? or outlet 14, through which the hot exhaust gases to be cleaned when flowing through the housing 10 have been introduced or discharged. Within the housing 10 i.9t a substantially cylindrical, honeycomb, nför: niges structure 16 arranged, the closer structure in FIG, ^-1.

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BATH ORIGINAL

is shown.

According to FIG. 2, the honeycomb structure 16 is cylindrical Assembly 18 with several corrugated layers 20, which are superimposed are arranged concentrically around an axis of the structural unit 18, as well as with a tubular intermediate layer !! 22, each are interposed between two radially adjacent corrugated layers 20. The corrugated layers 20 possess parallel backs, which extend over the entire length of the cylindrical structural unit 18 parallel to the axis thereof and with their upper and lower apices alternate with the surfaces of the molded intermediate layers 22 are attached. Accordingly, between the corrugated layers 20 and the surfaces the intermediate layers 22 form a series of through channels 24, which open towards the ends of the cylindrical assembly 18. As previously mentioned, the corrugated layers 20 and 20 are tubular intermediate layers 22 made of sintered ceramic of an aluminum oxide, v / ie for example made of sintered dichroic (cordierite) manufactured. They are therefore provided with fine (not shown) gaps or pores with which the cleaning of the The catalytic converter that promotes the exhaust gases is filled. The in this way The cylindrical structural unit 18 constructed is comprised of an outer layer 26 of sintered porous or non-porous ceramic material surrounded, which be a mass such as ß -spodumene kamr, which becomes glass-like when sintered.

According to FIG. 1, the honeycomb structure 16 is arranged inside the cylindrical housing 10 in such a way that the through channels 24 in the honeycomb structure open at their ends to the inlet 12 and outlet 14 of the housing. A pair of stops 28 and 30 are attached to or formed on the housing 10; they are arranged next to the edges of the outer layer 26 of the honeycomb structure 16. The stops 28 and '60 are therefore close to the edges of the outer layer 26 of the honeycomb structure 16,

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so that they the honeycomb structure 16 immovable within of the housing 10 or prevent the honeycomb structure 16 from moving in the longitudinal direction out of the prescribed working position moved within the housing 10. The attacks 28 and JO are shown here as a bracket attached to the inner Tlmfangsfläche of the housing 10 are welded. This execution The attack is only to be understood as an example and the honeycomb structure 16 can be held in position in any desired manner. It is only necessary that the stops support the edges of the outer layer 26 of the honeycomb structure 16. With 32 a cylindrical buffer is designated, which is preferably between the inner circumferential surface of the housing 10 and the outer layer 26 of the honeycomb structure is arranged in order to mitigate shocks and vibrations, from the housing 10 built into the exhaust system of an internal combustion engine, for example, onto the honeycomb structure 16 could be transferred.

To produce the heat-resistant wabci} -förniigen structure 16 shown in FIG. 1, a paper pulp (paperni'-king pulp stock) is first prepared, which is carefully processed into a mass by stirring (beating) or refining (refining) will. Particles of a suitable ceramic material, preferably aluminum oxide, such as dichroic, which is pulverized to a certain grain size, are dispersed or distributed in the pulp, advantageously in a ratio of 7 to 15 or more, but preferably of about 10 parts by weight of ceramic material per part by weight of pulp. The resulting dispersion or suspension of the ceramic material and the fibers in the pulp is then converted into a structure according to Pig, for example with the aid of a press die (extrusion tool). 2 generated. Alternatively, the suspension or sludge mass to cardboard covers provided with an elongated _v substantially flat layer and one corrugated layer is

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shaped with the corrugated layer having parallel ridges, laterally aligned with the corrugated sheet and attached to a surface of the flat sheet or with a Flat layer surface are one. The composite thus obtained Cardboard lid in the form of a longer stretched strip is then on the other surface of the flat layer with the crests of the corrugated layer firmly attached to the outer Circumferential surface of the originally flat layer and with the passages of the corrugated layer firmly on the inner peripheral surface of the originally flat layer into a cylindrical roll perol.lt. According to another alternative, the pulpy Ceramic dispersion a series of cylindrical cardboard lid parts increasing diameter, each of these parts being made from consists of a tubular layer and a corrugated layer with a back extending parallel to the r, ur axis of the cylindrical Partly extend and to a peripheral surface of the tubular Layer are attached. The cylindrical cardboard cover parts produced in this way are then fastened concentrically to one another, whereby a roll with a shape corresponding to FIG. 2 arises.

The cylindrical cardboard lid structure, which was manufactured from the pulpy ceramic dispersion in one of the ways described above, is then fired at a temperature below the melting temperature of the ceramic material contained in the cardboard lid, so that the structure becomes spongy, ie it has a large number of pores, resulting from the burning of the fibers in the original pulp. The sponge-like pastry produced in this way is held in its entirety in a cylindrical shape, which is composed of a series of through-channels that are bordered by the backs of the corrugated layers and by the tubular swish layers, which now consist only of your ceramic material. After the goback has cooled down, it is placed in a cardboard lid with a Kerairik dispersion

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wrapped to a predetermined thickness or in a desired number of layers on the outer peripheral surface of the cylindrical Pastry is twisted. Distributed in the pulp to form the cardboard lid to be wrapped on the pastry Ceramic material is advantageously a mixture such as, for example

β -spodumene, which, as previously mentioned, can form a glass-like product. In this case it is important that such a ceramic material is chosen for the cardboard lid for wrapping the biscuits, the melting temperature of which is lower than the melting temperature of the ceramic material contained in the cardboard lid from which the cylindrical structure was originally constructed. The ceramic material which will ultimately form the outer layer can, however, be chosen so that a porous outer layer is formed.

The pastries wrapped in this way with the additional layer of cardboard cover the ceramic material forming the inner baked goods is then fired from the ceramic material at a sintering temperature, see above that the pastry is finally sintered and at the same time the ceramic material contained in the outer layer becomes a non-porous cylindrical jacket is melted or sintered.

That for the formation of the outer layer of the roller-shaped structure with the hio.r proposed shape selected ceramic material can be similar to the ceramic material making up the selected layers and the intermediate layers, but with a lower melting temperature possess as the latter ceramic material. It is therefore desired that the constituting the corrugated layers and spacers Ceramic material is also used to build the outer layer of the honeycomb structure, then the ceramic material should be used a suitable metal oxide can be admixed in order to lower the melting temperature of the ceramic material for the outside world. If the same type of ceramic material is used to construct the honeycomb structure and the outer layer,

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then, as shown in FIG. 3, before firing, an elongated strip 34 of a cardboard lid with a ceramic dispersion, the finally the outer layer 26 (FIG. 2) of the honeycomb structure forms, on the outer peripheral surface of the cylindrical structure of the corrugated and tubular cardboard cover layers to be wrapped. In this case, the overall unit should consist of the honeycomb structure and the outer layer made of cardboard lid with ceramic dispersion, to be fired at a sin.tertemperature of the ceramic material in the cardboard lid to build up the corrugated layers and the intermediate layers is, so that the layers forming the uaben-shaped structure be sintered to fit and at the same time, in a single pass, the layer for forming the outer jacket is melted.

If, on the other hand, a ceramic mixture is used to form the outer layer and the honeycomb structure, which becomes vitreous when melted, such as ß -spodumene, then particles of the ceramic mixture can be applied directly to the outer peripheral surface and, if desired, to an outer peripheral surface of each edge of the pastry obtained in the first firing step of the formation of the cardboard cover layers. The cylindrical baked goods coated in this way with the pulverized ceramic mixture are then fired at a temperature close to the sintering point of the ceramic material making up the inner baked goods, so that, as can be seen in FIG fuse corrugated layers 20 and intermediate layers 22 together. According to Fig. 4-, the jacket 36 is not only formed on the outer cylindrical surface of the structure from the layers 20 and 22, but also, as indicated at 36a, on annular portions which are firmly attached to the outer circumference of the edges of the layers 20 and 22 are arranged.

The method for producing the heat-resistant one of the present invention honeycomb structure is explained in more detail below with the aid of examples.

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Example I.

First, a pulp (pulp stock) was prepared in which dichroic particles were distributed in a weight ratio of 10 parts of dichroic to 1 part of pulp. The material thus obtained was formed into an elongated strip of cardboard cover having a substantially flat layer and a corrugated layer with parallel spines aligned laterally on the corrugated layer and attached at their bottoms to a surface of the flat layer. The elongated strip was then rolled onto the other surface of the flat sheet to produce a cylindrical structure with a diameter of 105 mm. The structure was then fired at a temperature of ⁰ I3OO G for 4 hours. Furthermore, an elongated strip of cardboard cover was prepared from a pulp stock with ß -spodumene distributed in it. The cardboard lid strip containing betta spodumene was wound to a thickness of 5 mm on the outer peripheral surface of the cylindrical biscuit obtained in the firing step. The resulting structure was then fired at a sintering temperature of dichroic, so that a honeycomb structure with sintered, porous, corrugated and intermediate layers and with a non-porous glass-like outer layer was obtained. For the formation of the outer layer, however, a ceramic material can also be selected which results in a porous outer layer.

Example II

As in Example I, a slurry containing dichroic particles was used to produce an elongated strip of cardboard cover with a flat layer and a split layer attached to the flat layer. The elongated strip was then rolled onto the outer surface of the flat layer into a cylindrical shape with a diameter of 100 mm «

309885 / UA1

A second elongated strip was made from a pulp stock in which particles of a mixture of dichroic and a metal oxide were dispersed. The second elongated strip was wound to a thickness of 3 mm on the outer peripheral surface of the cylindrical structure produced first. The overall structure obtained in this way was fired at a temperature of about 1 ° for 4 hours, resulting in a roller-shaped structure consisting of sintered, porous, corrugated and intermediate layers and a non-porous outer layer.

Example I II

As in Example I, an elongated strip of cardboard cover, consisting of a flat layer and a corrugated layer attached to a surface of the flat layer, was again produced from a pulp with dichroic particles distributed therein. The elongated strip was then rolled onto the other surface of the flat sheet into a cylindrical shape with a diameter of 110 nm. The cylindrical structure was then fired at a temperature of about 1300 ^° C. for 4 hours. Thereafter, ß spodumene particles were sprayed onto the outer circumferential surface of the cylindrical baked goods obtained during firing and onto outer circumferential or annular surfaces of the edges of the baked goods. The baked goods carrying the betta spodumene particles were then fired at a sintering temperature of the dichroite making up the baked goods, which resulted in a honeycomb structure consisting of sintered, porous, corrugated and intermediate layers and a glass-like outer layer, the latter covered the outer circumferential surface of the cylindrical structure composed of the corrugated and intermediate layers as well as the outer annular surfaces of the edges of the structure, as can be seen from FIG.

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Tests on the heat-resistant ones obtained in Examples I, II and III j honeycomb structures showed that not only all inner layers of the vault-shaped structure but also the outer layer surrounding the inner layers free of Was cracks. . ·

When using the heat-resistant, honeycomb-shaped structure produced by one of the methods or examples described above In a catalytic converter of the type mentioned above, the entire structure is converted into a solution of a preferred catalyst immersed so that the catalyst solution fills the pores in the sintered, porous layers of the structure. Pa in this Case the outer peripheral surface of the honeycomb structure of the non-porous outer layer is covered for the catalyst solution is impermeable, no catalyst will adhere to this particular area. Are still in accordance with .Yig. 4th annular covers 36a along the perimeter of the edges of the If the honeycomb-shaped structure is formed, the passage channels arranged next to the outer layer 5 ^ are rinf örrni p: en through this Covers 3Ga closed so that the KatalYsatorlÖimg does not can flow into these through channels. As mentioned, are The porous or non-porous covers on the honeycomb structures are advantageous in that they considerably reduce the mechanical Increase the strength of the structure.

If hot exhaust gases are now passed to the catalytic converter containing the cylindrical structure according to FIG. 1, the exhaust gases pass from the inlet 12 of the housing 10 into the passages 24 in the honeycomb structure 16. When flowing through these passages 24, the exhaust gases are grounded by post-combustion reactions that of that in the pores of the corrugated layers 20 and the intermediate layers 2? contained catalyst are promoted, cleaned. The cleaned exhaust · --->.;, C are then through the outlet 14 of the housing 10 into the

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submitted. When the hot exhaust gases continuously in this Flowing way through the catalytic converter becomes the v / a-shaped Formation 16 by the hot exhaust gases and by the heat of reaction in the post-combustion reactions of the harmful Components in the exhaust gases are heated.

Fig. 5 shows the general "course of the temperature distribution across the cross-sectional area of the honeycomb structure, the line c indicating the central axis of the honeycomb structure and the distance on the ordinate on either side of the crossing point c, which corresponds to the radial distance from the central axis. It is clear from the graph of Fig. 5 it can be seen that the temperature in the honeycomb structure is lowest near the outer diameter of the structure and the temperature increases in the direction of the central areas of the structure. This is partly due to the fact that on the one hand, the flow of exhaust gases from the near the periphery the edges of the honeycomb structure 16 arranged annular stops or brackets 28 and JO blocked and on the other hand the honeycomb structure 16 is cooled from its outer circumferential surface in the direction of the central regions of the ambient air.

Such an irregular temperature distribution within the honeycomb Formation, as shown in Fig. 5, would lead to an unbalanced radial expansion as in previously known honeycomb Formations lead if the outer layer 26 is not provided. local stresses within the honeycomb The result would be the formation of cracks and / or fractures when certain values were exceeded. These difficulties are completely overcome with the honeycomb structure that has the robust, porous or non-porous outer layer 26, which prevents irregular expansion of the honeycomb structure 16. In the honeycomb structure according to the invention

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Therefore, the corrugated layers 20 and the intermediate layers 22 become with the temperature distribution shown in FIG. 5 during heating only subjected to compressive forces. Since the honeycomb structure 16 is made up of sintered layers 20 and 22, the are sufficiently resistant to compressive forces, neither cracks nor fractures occur in it, even if it is a relatively irregular one Temperature distribution is exposed. ITupon completion the flow of hot exhaust gases through the catalytic converter can eich the honeycomb structure 16 cool down again. The corrugated layers 20 and intermediate layers 22 are thereby gradually released from the compressive forces without being exposed to significant tensile forces.

The arrangement of the outer layer 26 also increases the mechanical strength of the roller-shaped structure 16 against forces that act in the axial direction on the structure. Becomes the outside diameter of the cylindrical structure, consisting of the corrugated layers and intermediate layers, denoted by D, and is the thickness of the outer layer t covering the structure, then the mechanical strength of the honeycomb structure increases with the outer reinforcement layer 26 in the axial direction an increase in the value t / D, as tests carried out have proven and the table below shows. The one in this The strength values listed in the table are based on the value 100, which is the mechanical strength in the axial direction corresponds to a honeycomb structure made of cardboard cover with ceramic dispersion, but no outer reinforcing layer having.

Previously known
Erzeufcni s Attempt 4- pieces (inventi 8th 10 t / DV / ert % 0 2 170 6th 260 310 axial strength ^c yes 100 130 210

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With these test pieces v / ere also under rapidly changing conditions V / ärmestoßtests carried out in which the test pieces in 30 seconds at 800 ⁰ C were heated and then cooled 'in 1 minute at 200 ° C. The result was that neither cracks nor fractures occurred in the test pieces and the outer layers did not detach from the honeycomb-shaped structures.

The thickness of the outer layer can take into account the total weight and / or the desired axial strength of the honeycomb structure. V / ird there are honeycomb structures held in position by means of suitable supports, for example the stops 28 and 30 shown in Fig. 1, then the Thickness of the AuC-en: .-. Chicht: 'o burrowed that they are essentially is equal to the radial extension of the annular stop, which in this case is designed as a bracket *

From the preceding Γ-e spelling it became clear that the The honeycomb structure proposed here has an outer reinforcing layer made of porous or non-porous material and accordingly, against thermal and mechanical loads resistance, which usually leads to cracks and breaks in the v / but creamy structure would lead if the structure were a irregular temperature distribution, thermal shock3 and / or mechanical shocks and vibrations. The arrangement of the Au core layer also reduces wear on the front edges of the honeycomb structure due to sliding movements of the corresponding Sections on the parts carrying the honeycomb structure.

Because of the advantages mentioned, the one proposed here is suitable honeycomb structures for those applications in which the honeycomb structure has an elevated temperature, uneven temperature distribution; and sudden temperature changes accompanied by mechanical. Is exposed to shocks and vibrations.

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Claims (1)

Patent claims: Itzebe permanent s roller-shaped structure, gel "e η η ζ ei cbn et by several [corrugated layers (20) and Zv / i already layers (22) of porous ceramic material, which are arranged in alternating order on top of each other, v / whether the corrugated layers have parallel backs attached at their upper and lower portions to the surfaces of adjacent intermediate bearings, thereby forming a number of through channels (2A) extending parallel to the backs and from the chucks and surfaces of the adjacent ones Intermediate layer]! And by at least one outer layer (26,34 * 36) made of ceramic material, which surrounds the structure of the corrugated layers and intermediate systems in v / es en ti 5. just cjusr to the back, so that at least a large part the through cannula is kept open at its opposite ends. 2.Gebild.e according to claim 1, characterized geke η η ζ calibration et η- that the porous ceramic sintered material is Aluminiunoxyd ':. 3. Structure according to claim 2, characterized in that that the aluminum oxide is Mchroi.t (cordierite). 4-. Structure according to one of claims 1 to 3 »characterized in that g e k e η; ■; -draws, that the outer layer (26,34,36) made of ceramic material is porous. 5. Structure according to claim 4, characterized in that h η e t, that the outer layer (26,34,36) of Kerarnilcraaterial from particles is constructed, which are the same or similar in size to the particles of the porous Keraiaiknaterialc. 309885 / UA1 6.Gebilde according to one of claims 1 to 3 »characterized in that the outer layer (26,34,36) made of ceramic material is non-porous. 7. Structure according to claim 6, characterized in that that the outer layer (26,34,36) made of ceramic material from particles is constructed, which are the same or similar in size as the particles dec porous ceramic material. 8. Structure according to claim 7? characterized, that the ceramic material (of the outer layer) is β-spodumene. 9. Structure according to claim 7 »characterized in that that the Koramikmaterial contains a metal oxide as an additive and the mixture of the ceramic material and the metal oxide has a lower melting point than the porous ceramic material. 10.Gebilde according to one of claims 1 to 9 _t, characterized in that it has a cylindrical shape. 11.Gebilde according to claim 10, characterized by a pair of annular ceramic layers (36a), the outer non-circular surfaces of the ends (end faces) of the structure (16 ") and the opposite ends from near the outer layer (26,34,36) arranged through channels (24) complete. 12.Gebilde according to claim 10 or 11, characterized in that the corrugated layers (20), the Zv / icchenlagen (22) and the outer layer (26,34,36) are arranged concentrically around the longitudinal axis of the structure. 309885/1441 13-method of making a heat-resistant honeycomb-shaped Structure, characterized by the process steps: Creation of a structure of corrugated layers (20) and intermediate layers (22) in an alternating sequence of cardboard cover (paper board) from a pulp mass (Papicrbrei-pulp stock) with ceramic material distributed therein, so that the corrugated layers have parallel backs on their upper and lower portions for forming through-channels (24-) are attached to the surfaces of adjacent intermediate layers, firing the created structure at a temperature lower than the melting point of the ceramic material contained in the cardboard lid to obtain a "biscuit", and forming a Outer layer (26.3 ² N36) made of ceramic material, which becomes glass-like when it melts, for covering the pastry in such a way that at least a large part of the through channels remains open at their opposite ends. 4. The method according to claim 13 »characterized in that that the ceramic material distributed in the cardboard lid is aluminum oxide. 15. The method according to claim 14, characterized in that t _? that the alumina is dichroic. 16. The method according to one of claims I3 to I5, characterized in that ekennzeich.net, that the porridge races with that distributed in it Ceramic material 7 to 15 parts by weight ceramic material to 1 part by weight of paper pulp. 17. The method according to claim 16, characterized in that the pulp with the ceramic material distributed therein 10 parts by weight of ceramic material to 1 part by weight Contains paper pulp. 309885 / 14A1 233703A 18. The method according to one of claims 13 to 17 »thereby • indicates that the ceramic material (for the outer layer) is β-spodumene. 19. Ancestors according to one of claims 13 Ms 18, characterized in that the outer layer (26,24,36) by wrapping the pastry essentially across the jackets the corrugated layers (20) is formed in at least one layer from the cardboard cover which is made from the ceramic material containing paper pulp is formed, which ceramic material becomes vitreous on melting, and that the structure obtained is fired at a temperature close to the sintering temperature of the ceramic material making up the baked goods. 20. The method according to one of claims 1; 5 to 18, characterized in that the outer layer (26,34 · j36) by spraying particles of a ceramic material, which becomes vitreous when melted, onto the outer surface of the Pastry is produced that is parallel to the back of the corrugated Layers (20) so that at least a large part of the 'Durchgargckanäle (24) are at their opposite ends remains open, and that the pastry together with the sprayed-on particles at a temperature close to the sintering temperature of the ceramic material making up the pastry. ^ ebramit v / ird. .Method according to one of claims 15 ds c. j * denotes that the ceramic material which forms the outer layer (26,34,36.) has the same or similar particle size, but a lower melting temperature than the ceramic material contained in the paper pulp. 309885 / U41 22. The method according to claim 21, characterized in that et that the outer layer (26,34,36) constituting ceramic material contains a metal oxide as an additive. '23. Method., According to claim 21, characterized in that it is marked e t that the outer layer (26,34,36) by wrapping the structure substantially transversely to the back of the corrugated Layers formed in at least one layer from the cardboard cover produced from the paper pulp containing the ceramic material, which ceramic material is the same or similar particle size, but has a lower melting point than that dispersed in the pulp Ceramic material, and that the structure obtained with the outer layer consisting of at least one layer at a Temperature close to the sintering temperature of the pulp distributed ceramic material is fired. 24.Vorrichtung sum.Durchleiten hot gases, characterized by a housing (10) with an inlet (12) and an outlet (14) for the hot gases to pass through * through the housing, a heat-resistant "honeycomb-shaped structure, consisting of several corrugated layers (20) and intermediate bearing (22) made of porous Ecrarnikmaterial, which in alternating Sequence are arranged with the corrugated layers having parallel ridges on their upper and lower Sections on the surfaces of adjacent intermediate !! agen are attached and are essentially in the direction of the entrance and the outlet of the housing, thereby creating a number of through channels (24) extending from the backs of the corrugated Layers and the surfaces of the. adjacent intermediate layers are delimited and attached to their opposite Open ends to the inlet and outlet continues from an outer layer (26,34,3G) from Kerai.iikmatcrial, which the structure of the corrugated layers and intermediate !! η ^ oμ 3Q9885 / U41 surrounds and tightly against the back essentially transversely to the back an inner peripheral surface of the housing rests, as well as by a pair of stops (28,50)? those on the inner circumferential surface of the housing and support the edges of the outer layer. 2 | 5. Device according to spoke 24, characterized by a pair of non-porous layers (36a) made of the ceramic material, those on outer circumferential surfaces of the edges of the structure of the corrugated layers (20) and intermediate layers (22) are attached and opposite ends of the near the outer layer (26.3 ^ »3 · - ·) arranged through channels (24) to lock. 26.Vorrichtung according to claim 2A- or 25, characterized in that the stops (28,30) extend as far as the end faces of the outer layer (26,34-} 36). 27.Vorrichtung according to any one of claims 2A to 26, characterized in that the pores of the porous ceramic material are filled with a catalyst which is effective for cleaning the exhaust gases of an internal combustion engine. 309885 / U41